1. Field of the Invention
The invention relates to an electric door lock, more particularly to an electric door lock that is operable in locking and unlocking modes both manually and electrically.
2. Description of the Related Art
A conventional electric door lock, which is operable in locking and unlocking modes both manually and electrically, includes a lock housing that confines an accommodating space. The lock housing is formed with a handle mounting hole therethrough. A manual operating member is mounted rotatably on the lock housing, and has an operating spindle that is disposed in the accommodating space and that extends through the handle mounting hole, and a manually operable rotary handle that is secured to one end of the operating spindle and that is disposed externally of the accommodating space. A first snap ring is secured to the operating spindle proximate to the manually operable rotary handle. A gear wheel is sleeved rotatably on the operating spindle, and has a first surface that abuts against the first snap ring, and a second surface that is opposite to the first surface of the gear wheel and that is formed with ratchet teeth. An actuating member is sleeved on the operating spindle so as to permit co-rotation of the actuating member with the operating spindle and axial movement of the actuating member relative to the operating spindle. The actuating member has a first surface that confronts the second surface of the gear wheel and that is formed with ratchet teeth, and a second surface that is opposite to the first surface of the actuating member. A second snap ring is secured to the operating spindle. A biasing spring is sleeved on the operating spindle, and has opposite ends abutting respectively against the second surface of the actuating member and the second snap ring. The biasing spring provides a biasing force for biasing the actuating member toward the gear wheel. An electric driving motor unit is mounted in the accommodating space and is operable so as to drive rotation of the gear wheel.
In operation, when the electric driving motor unit drives rotation of the gear wheel, the ratchet teeth on the second surface of the gear wheel engage the ratchet teeth on the first surface of the actuating member. Accordingly, the actuating member and the operating spindle rotate with the gear wheel. On the other hand, when a rotating force is applied directly to rotate the manually operable rotary handle of the manual operating member, since rotation of the gear wheel is resisted by the electric driving motor unit, the ratchet teeth on the first surface of the actuating member slide past the ratchet teeth on the second surface of the gear wheel. Accordingly, rotation of the actuating member with the operating spindle does not result in corresponding rotation of the gear wheel.
The actuating member is rotatable relative to the lock housing between first and second angular positions such that the electric door lock is operable in the locking and unlocking modes, respectively. In particular, the actuating member includes a switch actuator mounted on the second surface of the actuating member so as to permit co-rotation of the switch actuator with the actuating member. The switch actuator has a switch actuating portion that extends in radial outward, direction.
The electric driving motor unit includes an optoelectric switch that is activated and deactivated by the switch actuating portion when the resilient actuating member is rotated to the first and second angular positions, respectively. Hence, the optoelectric switch is actuated by the switch actuating portion when the electric door lock is in the locking mode, and is deactivated when the electric door lock is in the unlocking mode.
Although the aforementioned conventional electric door lock achieves its intended purpose, it requires numerous parts, which results in higher production costs and a larger size for the door lock.
Therefore, the object of the present invention is to provide an electric door lock that can overcome the aforesaid drawback of the prior art.
According to the present invention, an electric door lock for a door panel comprises a lock housing, a manual operating member, a gear wheel, a resilient actuating member, an electric driving motor, and a releasable coupling unit. The electric door lock is operable in locking and unlocking modes. The lock housing is adapted to be mounted on the door panel, is formed with a handle mounting hole, and confines an accommodating space. The manual operating member is mounted rotatably on the lock housing, and has an operating spindle that is disposed in the accommodating space and that extends through the handle mounting hole, and a manually operable rotary handle that is secured to one end of the operating spindle and that is disposed externally of the accommodating space. The gear wheel is sleeved rotatably on the operating spindle. The resilient actuating member has a securing portion secured to the operating spindle so as to permit co-rotation of the resilient actuating member with the operating spindle, an abutting portion disposed adjacent to the gear wheel, and a resilient connecting portion that extends from the securing portion to the abutting portion and that urges the abutting portion toward the gear wheel. The electric driving motor unit is mounted in the accommodating space and is operable so as to drive rotation of the gear wheel. The releasable coupling unit is provided on the gear wheel and the abutting portion of the resilient actuating member for coupling releasably the gear wheel and the resilient actuating member. The releasable coupling unit interconnects the gear wheel and the resilient actuating member such that the resilient actuating member and the operating spindle rotate with the gear wheel when the electric driving motor unit drives rotation of the gear wheel, and disconnects the resilient actuating member from the gear wheel when a rotating force is applied directly to rotate the manually operable rotary handle of the manual operating member such that rotation of the resilient actuating member with the operating spindle does not result in corresponding rotation of the gear wheel.